In alarm systems, such as building fire alarm systems, it is desirable to have audio capabilities. Audio capabilities enable emergency messages to be passed between fire control panels and/or audio panels in an alarm system. As public safety is impacted by building alarm systems, standards have been developed by organizations in the United States and Europe.
Some standards, such as UL 864 9th Edition and 5527 3rd Edition require the audio paths to be monitored to assure their operational status. Methods have been developed and deployed in the past to monitor audio paths external to the fire control panels and audio control panels.
Current technology processes audio signals in the digital domain within and between semiconductor chips. But current standards require the monitoring of these portions of the audio bus. The known approaches fail to monitor inter-chip audio paths and buses between semiconductor chips. What is needed in the art is an approach that enables monitoring the audio paths internal and external to the semiconductor chips in an efficient way while reducing the amount of additional circuitry required.